UV Sweeper Instructions

 

3DReefing UV Sweeper — Usage & Best Practices Guide  

Updated Jan. 2026

 

Quick Summary

  1. Identify dinos using a microscope to confirm they are sand-dwelling types (e.g., Amphidinium, Prorocentrum).

  2. Treat daily by sweeping the UV light across the top layer of the sandbed for 10–15 seconds per area during peak lighting hours.

  3. Immediately follow treatment with a dose of bottled bacteria and shut off all flow for 30 minutes. Leave protein skimmer off for at least 4 hours.

  4. Continue daily for 10–14 days even if the tank looks clear. Confirm success under a microscope.

  5. Maintain nutrients within the ideal range (PO4: 0.04–0.08 ppm, NO3: 5–10 ppm) to support long-term stability and prevent recurrence.

  6. Do not combine with other treatment methods such as silicate dosing, which can interfere with visibility and reduce effectiveness.

STEP 1 - Daily UV Treatment Instructions

Note: If certain areas of your tank are physically difficult to reach with the UV Sweeper, treat as much of the sandbed as you can. Many users report that even hard-to-reach areas begin to clear up on their own once the majority of the sandbed is consistently treated. Focus on thorough coverage where possible, and continue the process daily.

Objective: Sterilize dinoflagellates located on the top layer of the sandbed during peak lighting hours when they are most active.

  1. Identify visible dino outbreak zones during peak lighting periods.

  2. Hold the UV Sweeper as close as possible to the sand without disturbing it.

  3. Treat each targeted area for 10–15 seconds. Longer exposure is not necessary.

  4. Move methodically across the sandbed to ensure complete surface coverage.

  5. Repeat this process once daily for 10–14 consecutive days, even if the sand appears clear.

DO NOT DOSE SILICATES TO INDUCE A DIATOM BLOOM WHILE USING THE UV SWEEPER TREATMENT!  Recent cases have shown this will prolong the process.  

Tip: Use a microscope to confirm presence or absence of dinos before ending treatment.

STEP 2 - Post Treatment Bacteria Dosing

It is important to dose the bottled bacteria immediately after each UV treatment. Follow the dosage recommendations provided on the product label. 

Following each UV session:

  1. Dose a high-quality bottled bacteria to help reestablish microbial balance in the sand bed. (Recommended bottled bacteria below)

  2. Turn off all flow (wavemakers and return pump) for 30 minutes after dosing to allow the bacteria to settle.

  3. Turn off your protein skimmer for a minimum of 4 hours. The longer it remains off, the better, as skimming will remove beneficial bacteria from the water column during this critical recolonization window.

  4. Ensure any UV sterilizers plumbed into your system are turned off and remain off for the entire duration of the treatment cycle. Running a system-wide UV sterilizer during this process is counterproductive, as it can eliminate the very bacteria needed to shift the microbiome and keep dinos from returning.

  5. Do not use other methods such as silicate dosing during the UV Sweeper treatment process. The UV light will sterilize diatoms along with dinos, making silicate dosing ineffective and potentially counterproductive by obscuring infected areas from sterilization.

Recommended Bacteria (in order of effectiveness):

  • Microbe-Lift Special Blend

  • Hydrospace ProBio (Less smell)

Alternate Options (if PNS smell is an issue):

  • Brightwell Microbacter7 

Bacteria should be dosed daily in conjunction with UV treatment throughout the 10–14 day cycle.  Choose one type of bottled bacteria and do not mix them or use different types with in 24hours of dosing.  

Not required but always beneficial:

  • Source and dose high quality LIVE phytoplankton after each treatment.  Live phytoplankton will lower your nutrients.  Unalive phyto will increase nutrients.  Monitor closely.  

 

Treatment Duration & Follow-Up

  • Continue treatment for 10–14 days, regardless of visual improvement.

  • Do not stop early; dinos can persist microscopically.

  • Confirm complete eradication using a microscope before discontinuing treatment.

Understanding the Root Causes of Dino Outbreaks

To permanently eliminate dinoflagellates from your reef tank, it’s essential to address the conditions that allowed them to take hold in the first place. While the UV Sweeper effectively sterilizes dinos on the sandbed, lasting success depends on identifying and correcting the root causes.

Common Contributors to Dino Blooms:

  • Nutrient Instability — Both bottomed-out nutrients (near 0 ppm) and excessively high levels can lead to imbalances that promote dinos. Systems that hit 0 nitrate or phosphate often suffer weakened microbiomes, while those with phosphate above 0.1 ppm or nitrate above 10 ppm may fuel dino growth directly.

  • Excess Amino Acids — Overdosing amino acids can enrich the environment in a way that favors dinoflagellates.

  • Elevated Iron or Trace Element Imbalance — Imbalances revealed in ICP tests, particularly elevated iron, have been linked to persistent outbreaks.

  • Improper Lighting Spectrum — We are still investigating the best spectrum but recent developments have shown that a whiter spectrum is better for shifting the microbiome.  Unnatural extended deep blue spectrums may inhibit competing organisms from flourishing while at the same time fuel the more brown nuisance organisms.  We encourage users to experiment cautiously with changing the lighting spectrum.  The recommendation is increasing the white channels to at least 15-20% of the blue channels.  Each reef light can be different.  

  • Un-Maintained RODI System — Make sure your RODI unit filters are well maintained.  Even when total dissolved organics monitors show 0 there may still be unknown pollutants getting through.  Even an ICP test will not pick up these unknowns.  The most important part is making sure your color changing resin is not indicating more than 3/4 exhaustion.  

 

Note: These recommendations are based on extensive trial and error using the UV Sweeper. During repeated testing, it was observed that tanks with elevated phosphate (above 0.10 ppm) and nitrate (above 10ppm) levels outside this range struggled significantly more to eliminate dinos.

Why Balance Matters: 

Dinos thrive in extremes. The ideal approach is to bring your tank’s environment into a balanced “Goldilocks zone” where beneficial bacteria can outcompete nuisance organisms. For most systems, this means keeping:

  • Phosphate (PO4): 0.04 – 0.08 ppm

  • Nitrate (NO3): 5 – 10 ppm

Stabilization Tips:

  • Add a refugium with macroalgae (such as chaeto or ulva)

  • Install a turf scrubber if stronger export is needed

  • Reduce feeding or livestock if nutrient export cannot keep up

  • (Still in testing) Aggressive bacteria such as Brightwell Microbacter Clean may help in lowering nutrients when others can not.  It is advised to be cautions with this one as it could be too aggressive and make the outbreaks worse.  Only recommended in extreme high nutrient cases.

Correcting these underlying issues ensures your microbiome remains strong and resilient, making future dino blooms far less likely. Even more importantly, these same adjustments benefit your reef tank as a whole. Proper nutrient balance, trace stability, and microbiome support are fundamental not just for defeating dinos, but for overall coral health and for preventing a wide range of other nuisance organisms. It's not just dino prevention—it's good reefing practice.

Troubleshooting

Still seeing dinos after 14 days?

  • Recheck phosphate and nitrate levels

  • Verify dino presence microscopically

  • Consider trace element imbalance (use ICP testing)

  • Review any amino acid or iron dosing practices

  • Double check RODI system

Reappearance weeks later?

  • Microbiome may not have fully shifted

  • Resume the 10–14 day treatment cycle with bacteria support

  • Reassess nutrient stability and trace element balance

Long-Term Success

The UV Sweeper is a reliable solution designed to eliminate sand-dwelling dinoflagellates and support the restoration of a balanced reef environment. When used correctly alongside nutrient stabilization and beneficial bacteria dosing, most systems experience a full and lasting recovery.

Once the microbiome has successfully shifted and the outbreak is resolved, further use of the UV Sweeper is typically unnecessary. With proper nutrient management and continued microbial support, your tank can remain dino-free for the long term.

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